Background:Exercise induces blood flow redistribution among tissues,leading to splanchnic hypoperfusion.Intestinal epithelial cells are positioned between the anaerobic lumen and the highly metabolic lamina propria wi...Background:Exercise induces blood flow redistribution among tissues,leading to splanchnic hypoperfusion.Intestinal epithelial cells are positioned between the anaerobic lumen and the highly metabolic lamina propria with an oxygen gradient.Hypoxia-inducible factor(HIF)-la is pivotal in the transcriptional response to the oxygen flux.Methods:In this study,the pimonidazole hydrochloride staining was applied to observe the tissue hypoxia in different organs,which might be affected by the blood flow redistribution.The HIF-la luciferase reporter ROSA26 oxygen-dependent degradation domain(ODD)-Luc/^+mouse model(ODD domain-Luc;female,n=3-6/group) was used to detect the HIF-la expression in the intestine.We used 3 swimming models:moderate exercise for 30 min,heavy-intensity exercise bearing 5% bodyweight for 1.5 h,and long-time exercise for 3 h.Results:We found that 1 session of swimming at different intensities could induce tissue hypoxia redistribution in the small intestine,colon,liver and kidney,but not in the spleen,heart,and skeletal muscle.Our data showed that exercise exacerbated the extent of physiological hypoxia in the small intestine.Next,using ODD-Luc mice,we found that moderate exercise increased the in vivo HIF-1α level in the small intestine.The postexercise HIF-1α level was gradually decreased in a time-dependent manner.Interestingly,the redistribution of tissue hypoxia and the increase of HIF-la expression were not related to the exercise intensity and duration.Conclusion:This study provided evidence that the small intestine is the primary target organ for exercise-induced tissue hypoxia and HIF-la redistribution,suggesting that HIF-1α may be a potential target for the regulation of gastrointestinal functions after exercise.展开更多
The redistribution of the energy flow of tightly focused ellipticity-variant vector optical fields is presented.We theoretically design and experimentally generate this kind of ellipticity-variant vector optical field...The redistribution of the energy flow of tightly focused ellipticity-variant vector optical fields is presented.We theoretically design and experimentally generate this kind of ellipticity-variant vector optical field, and further explore the redistribution of the energy flow in the focal plane by designing different phase masks including fanlike phase masks and vortex phase masks on them. The flexibly controlled transverse energy flow rings of the tightly focused ellipticity-variant vector optical fields with and without phase masks can be used to transport multiple absorptive particles along certain paths, which may be widely applied in optical trapping and manipulation.展开更多
The growing penetration of electric vehicles(EVs)and the popularity of fast charging stations(FCSs)have greatly strengthened the coupling of the urban power network(PN)and traffic network(TN).In this paper,a potential...The growing penetration of electric vehicles(EVs)and the popularity of fast charging stations(FCSs)have greatly strengthened the coupling of the urban power network(PN)and traffic network(TN).In this paper,a potential security threat of the PN-TN coupling is revealed.Different from traditional loads,a regional FCS outage can lead to both the spatial and temporal redistribution of EV charging loads due to EV mobility,which further leads to a power flow redistribution.To assess the resulting potential threats,an integrated PN-TN modeling framework is developed,where the PN is described by a direct current optimal power flow model,and the TN is depicted by an energy-constraint traffic assignment problem.To protect the privacy of the two networks,an FCS outage distribution factor is proposed to describe the spatial-temporal redistribution ratio of the charging load among the remaining I FCSs.Moreover,to protect the security of the coupled networks,a price-based preventive regulation method,based on the spatial demand elasticity of the EV charging load,is developed to reallocate the charging load as a solution for insecure situations.Numerical simulation results validate the existence of the PN-TN coupling threat and demonstrate the effectiveness of the regulation method to exploit the spatial flexibility of EV loads.展开更多
基金supported by National Natural Science Foundation of China (Grant number:31471135,31701040, and 31801003)Shanghai Sailing Program (Grant number: 17YF1418000)Shanghai Municipal Education Commission (Grant number:Chenguang Program 16CG57)
文摘Background:Exercise induces blood flow redistribution among tissues,leading to splanchnic hypoperfusion.Intestinal epithelial cells are positioned between the anaerobic lumen and the highly metabolic lamina propria with an oxygen gradient.Hypoxia-inducible factor(HIF)-la is pivotal in the transcriptional response to the oxygen flux.Methods:In this study,the pimonidazole hydrochloride staining was applied to observe the tissue hypoxia in different organs,which might be affected by the blood flow redistribution.The HIF-la luciferase reporter ROSA26 oxygen-dependent degradation domain(ODD)-Luc/^+mouse model(ODD domain-Luc;female,n=3-6/group) was used to detect the HIF-la expression in the intestine.We used 3 swimming models:moderate exercise for 30 min,heavy-intensity exercise bearing 5% bodyweight for 1.5 h,and long-time exercise for 3 h.Results:We found that 1 session of swimming at different intensities could induce tissue hypoxia redistribution in the small intestine,colon,liver and kidney,but not in the spleen,heart,and skeletal muscle.Our data showed that exercise exacerbated the extent of physiological hypoxia in the small intestine.Next,using ODD-Luc mice,we found that moderate exercise increased the in vivo HIF-1α level in the small intestine.The postexercise HIF-1α level was gradually decreased in a time-dependent manner.Interestingly,the redistribution of tissue hypoxia and the increase of HIF-la expression were not related to the exercise intensity and duration.Conclusion:This study provided evidence that the small intestine is the primary target organ for exercise-induced tissue hypoxia and HIF-la redistribution,suggesting that HIF-1α may be a potential target for the regulation of gastrointestinal functions after exercise.
基金National Natural Science Foundation of China(NSFC)(11374166,11534006,11674184)National key research and development program of China(2017YFA0303700,2017YFA0303800)Natural Science Foundation of Tianjin City(16JC2DJC31300)
文摘The redistribution of the energy flow of tightly focused ellipticity-variant vector optical fields is presented.We theoretically design and experimentally generate this kind of ellipticity-variant vector optical field, and further explore the redistribution of the energy flow in the focal plane by designing different phase masks including fanlike phase masks and vortex phase masks on them. The flexibly controlled transverse energy flow rings of the tightly focused ellipticity-variant vector optical fields with and without phase masks can be used to transport multiple absorptive particles along certain paths, which may be widely applied in optical trapping and manipulation.
基金supported by Beijing Natural Science Foundation(No.JQ18008).
文摘The growing penetration of electric vehicles(EVs)and the popularity of fast charging stations(FCSs)have greatly strengthened the coupling of the urban power network(PN)and traffic network(TN).In this paper,a potential security threat of the PN-TN coupling is revealed.Different from traditional loads,a regional FCS outage can lead to both the spatial and temporal redistribution of EV charging loads due to EV mobility,which further leads to a power flow redistribution.To assess the resulting potential threats,an integrated PN-TN modeling framework is developed,where the PN is described by a direct current optimal power flow model,and the TN is depicted by an energy-constraint traffic assignment problem.To protect the privacy of the two networks,an FCS outage distribution factor is proposed to describe the spatial-temporal redistribution ratio of the charging load among the remaining I FCSs.Moreover,to protect the security of the coupled networks,a price-based preventive regulation method,based on the spatial demand elasticity of the EV charging load,is developed to reallocate the charging load as a solution for insecure situations.Numerical simulation results validate the existence of the PN-TN coupling threat and demonstrate the effectiveness of the regulation method to exploit the spatial flexibility of EV loads.
